Welcome to the Winobloggers webpage! Students and professors from different universities meet to discuss their findings on Winogradsky columns they constructed!
We learn how to formulate hypotheses, observe, comment, ask and reply to questions related to our scientific experiments.

Winogradksy columns

'In the field of observation, chance only favors the prepared mind' Pasteur 1854

Blog posts

Sunday, 21 May 2017

UCA_1C_Week 6

SECOND POSTHello! It´s been six weeks since we prepared our column and now it´s time to talk about the changes we have seen. Here we have some photos.

As we can see, at the bottom of the column it has appeared a black colour joined with a pink colour. We suppose that in this area there is not oxygen, so we can find microorganisms which are able to make fermentative processes.The waste of these microorganims is used by bacteria that reduce the sulphate. The result of this process is the liberation of sulphides. It goes to the top of the column which is oxygenated by cyanobacteria and algae.Also, there are photosynthetic bacteria that use the sulphur we can find in the column due to the sulphide gradient. Victoria, Andrea, Alessia.

2 comments:

Hi,I see a smal mixup of ideas... :-)1. what is the casue of the pink colour in the middle of the very black sediment you have atthe bootom?2. What is producing the black colour?3. Sulfides are not oxidised by cyanobacteria or algae (Sulfide is toxic to them). What hapens to the sulfide difusing upwards as you correctly say?4. I see a lot of light brown colour in your column. What is that?

1. We suppose that the pink colour is because there are purple bacteria and bacteria that reduced de CaSO4.

2. At the bottom of the column there is not oxygen, so we can find microorganisms which are able to make fermentative processes using sulfhate. In this process, it is produced SH2. A part of SH2 has reacted with the iron that we can find in the sediment we added and the result has been SFe (black).

3. Sulfide is used by bacteria which are in the middle of the column. They use SH2 as reducer, CO2 and chemical energy from light to produce their organic substance.4. The light Brown colour is the sediments we added.